be on (one's) best behavior

(redirected from on their best behaviour)

Like this video? Subscribe to our free daily email and get a new idiom video every day!

be on (one's) best behavior

To be very polite or exercise exceptionally good manners. Primarily heard in US. Now, you kids must be on your best behavior for your Auntie this weekend!Good morning, class. I hope everyone was on their best behavior for the substitute teacher yesterday.

All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.